Biomimetic Mg- and Mg,CO₃-substituted hydroxyapatites: synthesis characterization and in vitro behaviour

The doping of the apatite with carbonate or/and Mg ions in biologically-like amounts (6 and 1 wt.%, respectively) was performed. Chemico-physical characterizations and cell culture tests were carried out onto the synthetic Mg- and Mg,CO₃-substituted (∼30-40 nm particle size) powders in comparison with stoichiometric HA (∼160 nm particle size) to determine as mesenchymal stem cells (MSCs) can directly use the mineral microenvironment to stimulate their own proliferation and differentiation activities. At the same time the growth of human osteoblast like cells (MG-63) was evaluated to determine the compatibility of the synthetic doped apatites for bone substitution. Cell morphology analysis by SEM as well as MTT and ALP tests were performed. The peculiar chemico-physical properties of the doped (Mg- and Mg,CO₃-substituted) materials improved the behaviours of MSC and MG-63 cells in term of adhesion, proliferation and metabolic activation compared to stoichiometric HA.